<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div {
            width: 200px;
            height: 200px;
            background-color: pink;
            /*solid：实线 dashed：虚线 dotted：点线 */
            /*border: 3px solid red;*/
            border-bottom: 3px dotted yellow;
            border-top: 3px dotted yellow;
        }
    </style>
</head>
<body>
<div>文字</div>
</body>
</html>